<template>
    <div>
        <div class="goods">
            <!--分类-->
            <div class="menu-wrapper">
                <ul>
                    <li class="menu-item" v-for="(good,index) in goods" :key="index"
                        :class="{current:index===currentIndex}" @click="clickMenuItem(index)">
                        <span class="text bottom-border-1px">
                            <img class="icon" :src="good.icon" v-if="good.icon">{{good.name}}
                        </span>
                    </li>
                </ul>
            </div>

            <!--具体商品-->
            <div class="foods-wrapper" ref="foodsWrapper">
                <!--分类列表-->
                <ul ref="foodsUl">
                    <li class="food-list-hook" v-for="(good,index) in goods" :key="index">
                        <h1 class="title">{{good.name}}</h1>
                        <!--商品列表-->
                        <ul>
                            <li class="food-item bottom-border-1px"
                                v-for="(food,index) in good.foods"
                                :key="index"
                                @click="showFood(food)">
                                <div class="icon">
                                    <img width="57" height="57" :src="food.icon">
                                </div>
                                <div class="content">
                                    <h2 class="name">{{food.name}}</h2>
                                    <p class="desc">{{food.description}}</p>
                                    <div class="extra">
                                        <span class="count">月售 {{food.sellCount}} 份</span>
                                        <span>好评率 {{food.rating}}%</span>
                                    </div>
                                    <div class="price">
                                        <span class="now">￥{{food.price}}</span>
                                        <span class="old" v-if="food.oldPrice">
                                            {{food.oldPrice}}</span>
                                    </div>
                                    <div class="cartcontrol-wrapper">
                                        <CartControl :food="food"/>
                                    </div>
                                </div>
                            </li>
                        </ul>
                    </li>
                </ul>
            </div>
            <ShopCart/>
        </div>
        <Food :food="food" ref="food"/>
    </div>
</template>

<script>
    import BetterScroll from 'better-scroll'
    import {mapState} from 'vuex'
    import CartControl from "../../../components/CartControl/CartControl";
    import Food from "../../../components/Food/Food";
    import ShopCart from "../../../components/ShopCart/ShopCart";
    export default {
        name: "ShopGodds",
        data() {
            return {
                scrollY: 0, //右侧滑动的Y轴坐标
                tops: [], //所有右侧分类li的top组成的数组
                food: {} //需要显示的food
            }
        },
        mounted() {
            this.$store.dispatch('getShopGoods', () => {
                this.$nextTick(() => {
                    this._initScrooll()
                    this._initTops()
                })
            })
        },
        computed: {
            ...mapState(['goods']),
            // 计算得到当前分类的下标
            currentIndex() {
                const {scrollY, tops} = this
                const index = tops.findIndex((top, index) => {
                    // scrollY>=当前的top 并且小于下一个top
                    return scrollY >= top && scrollY < tops[index + 1]
                })
                return index
            }
        },
        methods: {
            _initScrooll() {
                new BetterScroll('.menu-wrapper', {
                    click: true
                })
                this.foodsScroll = new BetterScroll('.foods-wrapper', {
                    probeType: 2,
                    click: true
                })
                this.foodsScroll.on('scroll', ({x, y}) => {
                    this.scrollY = Math.abs(y)
                })
                this.foodsScroll.on('scrollEnd', ({x, y}) => {
                    this.scrollY = Math.abs(y)
                })
            },
            _initTops() {
                const tops = []
                let top = 0
                tops.push(top)
                const lis = this.$refs.foodsUl.getElementsByClassName('food-list-hook')
                Array.prototype.slice.call(lis).forEach(li => {
                    top += li.clientHeight
                    tops.push(top)
                })
                this.tops = tops
            },
            clickMenuItem(index) {
                // 把点击的左侧索引传递到右侧tops上
                const y = this.tops[index]
                // 立即更新右侧的scrollY为y
                this.scrollY = y
                this.foodsScroll.scrollTo(0, -y, 300)
            },
            showFood(food) {
                this.food = food
                this.$refs.food.toggleShow()
            }
        },
        components: {
            ShopCart,
            CartControl,
            Food
        }
    }
</script>

<style lang="stylus" scoped>
    @import "../../../common/stylus/mixins.styl"
    .goods
        display: flex
        position: absolute
        top: 195px
        bottom: 46px
        width: 100%
        background: #fff;
        overflow: hidden

        .menu-wrapper
            flex: 0 0 80px
            width: 80px
            background: #f3f5f7

            .menu-item
                display: table
                height: 54px
                width: 56px
                padding: 0 12px
                line-height: 14px

                &.current
                    position: relative
                    z-index: 10
                    margin-top: -1px
                    background: #fff
                    color: $green
                    font-weight: 700

                    .text
                        border-none()

                .icon
                    display: inline-block
                    vertical-align: top
                    width: 12px
                    height: 12px
                    margin-right: 2px
                    background-size: 12px 12px
                    background-repeat: no-repeat

                .text
                    display: table-cell
                    width: 56px
                    vertical-align: middle
                    bottom-border-1px(rgba(7, 17, 27, 0.1))
                    font-size: 12px

        .foods-wrapper
            flex: 1

            .title
                padding-left: 14px
                height: 26px
                line-height: 26px
                border-left: 2px solid #d9dde1
                font-size: 12px
                color: rgb(147, 153, 159)
                background: #f3f5f7

            .food-item
                display: flex
                margin: 18px
                padding-bottom: 14px
                bottom-border-1px(rgba(7, 17, 27, 0.1))

                &:last-child
                    border-none()
                    margin-bottom: 0

                .icon
                    flex: 0 0 57px
                    margin-right: 10px

                .content
                    flex: 1

                    .name
                        margin: 2px 0 8px 0
                        height: 14px
                        line-height: 14px
                        font-size: 14px
                        color: rgb(7, 17, 27)

                    .desc, .extra
                        line-height: 10px
                        font-size: 10px
                        color: rgb(147, 153, 159)

                    .desc
                        line-height: 12px
                        margin-bottom: 7px

                    .extra
                        .count
                            margin-right: 12px

                    .price
                        font-weight: 700
                        line-height: 24px

                        .now
                            margin-right: 8px
                            font-size: 14px
                            color: rgb(240, 20, 20)

                        .old
                            text-decoration: line-through
                            font-size: 10px
                            color: rgb(147, 153, 159)

                    .cartcontrol-wrapper
                        position: absolute
                        right: 0
                        bottom: 7px
</style>